1. Field of the Invention
This invention relates to a disk drive apparatus for driving or rotating a disk medium, and more particularly to a disk medium attaching device capable of releasably attaching a disk thereto.
More specifically, this invention relates to a medium attaching device for holding and releasing a concentric disk medium on a turntable, connected to a motor (rotating device for rotating this turntable), when this disk-like medium is to be driven for rotation. Here, the concentric disk-like mediums (disk media) include, for example, an old-fashioned EP record disk, an MO, a PD, a CD, a CD-ROM, a CD-R, a CD-RW, a DVD-ROM, a DVD-RAM or the like, and these disk mediums will be referred to merely as "disk".
2. Description of the Related Art
Conventional clamp mechanisms for a disk will be described. There have heretofore been used three kinds of clamp mechanisms described below. A first example of them is a disk self-holding type (clamp type) as disclosed in JP-A-9-147479, in which the user himself holds or grasps a disk, and attaches the disk directly onto a turntable which is a constituent part of an optical pickup. This disk holding means is called a ball chuck-type mechanism which comprises hard balls of metal or members of a resin for pressing the disk against the surface of the turntable.
A second conventional example is a mechanism as disclosed in JP-A-6-84255, in which a disk is transferred to a turntable by a disk loading mechanism, and is placed on a center hub, and then a fixing member (called a clamper), having a magnetic body, fixes the disk to the turntable from the upper side of the disk by its magnetic force. For transferring the disk, there is used, for example, a holder for holding a cartridge therein or a tray for placing the disk thereon.
A third conventional example is a method as disclosed in JP-P-61-264547, in which a disk is beforehand contained in a disk case called a cassette, and this cassette is inserted into a disk drive apparatus, and a clamp member, provided above the cassette, cooperates with a magnetic circuit formed by a magnet, provided in a turntable, so as to fix the disk to the turntable.
In each of these mechanisms, the disk is attached to the turntable or the holder by the operator. Therefore, it has been necessary to move the turntable or the holder to a position where this operation can be effected easily. The disk is attached, and the center thereof is aligned with that of the rotation drive portion of the disk drive apparatus, and then the clamp member moves downward to fix the disk. Therefore, it has been necessary to provide upwardly-moving and downwardly-moving mechanisms on the opposite (lower and upper) sides of the disk, respectively.
Recently, with the compact and thin design of disk drive apparatus, the disk drive apparatus is, in many cases, contained in portable personal computers. With this trendency, an optical pickup, which is a key device of the disk drive apparatus, has been required to have a more compact, thinner design. Software, used in computers, has now had a large capacity, and in many cases, inexpensive CD-ROMs have been used as media to be distributed. Therefore, it is now thought natural that the disk drive apparatus should be mounted on the personal computer.
However, the compact and lightweight design of computers has been advanced, and the disk drive apparatus, used as an external memory unit of the computer, has also been required to have a compact, lightweight design and a thin design. Therefore, the tray and the upwardly-moving and downwardly-moving mechanisms have been a barrier to the thin design. And besides, in order that a more comfortable operability of the computer can be provided, there has been a demand for the type of disk drive apparatus which does not require the attaching operation by the operator.